J. Black Sea/Mediterranean Environment Vol. 27, No. 1: 49-66 (2021) RESEARCH ARTICLE First massive mucilage event observed in deep waters of Çanakkale Strait (Dardanelles), Turkey H. Barış Özalp ORCID ID: 0000-0003-2640-8912 Vocational School of Ocean Engineering, Çanakkale Onsekiz Mart University, Çanakkale, TURKEY Faculty of Marine Sciences and Technology, Çanakkale Onsekiz Mart University, Çanakkale, TURKEY Corresponding author:
[email protected] Abstract During the regular surveys on coral monitoring for setting their developmental level, health status and likely threats responsible for mortality, a massive mucilage phenomenon was identified in the largest coral habitats in the Çanakkale Strait (Dardanelles) in December 2020. This study was performed to determine the effect of mucilage event on corals mainly observed at the depth level of 39-51 m in two stations, one in the European and the other in the Anatolian side of the strait. A massive mucilage with expanding cloud and floc types of aggregates was detected only in the Eceabat region (European side). A false-benthos mucilage was also identified at depths 4-20 m in the following control surveys. The current report is of the first circalittoral observation of this damaging event in the northernmost region of the Mediterranean Sea. Previous records of massive mucilage were reviewed and the first deep infralittoral record of massive mucilage event in 2008 is also described. Keywords: Mucilage, zoobenthos, coral, ecology, Turkish Straits System Received: 05.03.2021, Accepted: 05.04.2021 Introduction Mucilage, also known as marine snow, aggregated mass, foam accumulation, formation of flocs, cloud or mucilaginous and mucous agglomeration (Suzuki and Kato 1953; Riley 1963; Lancelot 1995; Rinaldi et al.